As disclosed in Japanese Patent Application Laid-Open No. 171986/1986 (JP-A-61-171986), as hoses of this type, there has been known a hose formed by, without a hard steel wire, molding a circumferential wall of a polyethylene or the like such as to be corrugated along the axial direction (so called conduit hoses in this field). Such hoses are not liable to be permanently deformed even if they are treaded.
However, since the wall of the conduit hose is configured such as to become corrugated relatively high to enhance its strength against crush, there has been a problem that when an end of the hose is connected firmly to a joint for a drive unit or a joint for an operation unit for an electric cleaner, a spirally or helically extending concave groove formed inside the circumferential wall acts as an air passageway slightly communicating with the outside and, therefore, inflow air from the outside reduces the suction force. To solve this problem, an annular protrusion is formed along the circumference of the joint, which an end of the hose abuts with, and the gap therebetween is sealed with an adhesive or the like. however, such sealing treatment is troublesome and inefficient.